Anatomy of stem in some Euphorbiaceae –II

This communication includes stem anatomical characteristics of 17 species of the 17 euphorbiaceous genera. The observations pertain to the epidermis, hypodermis, cortex, vascular tissues and pith. The cell wall contours have been described in detail. Occurrence of cell inclusions is also noted in different tissues of the stem – axes. The authors are inclined to state that the anatomical features of stem axes are taxonomically significant

Micromorfología y anatomía foliar de Myrceugenia rufa (Myrtaceae). Un arbusto costero endémico de la zona centro-norte de Chile

Species of fleshy-fruited Myrtaceae are generally associated with humid environments and their vegetative anatomy is mainly mesophytic. Myrceugenia rufa is an endemic and rare species from arid zones of the coast of central Chile and there are no anatomical studies regarding its leaf anatomy and environmental adaptations. Here we describe the leaf micromorphology and anatomy of the species using standard protocols for light and scanning electron microscopy. The leaf anatomy of M. rufa matches that of other Myrtaceae, such as presence of druses, schizogenous secretory ducts and internal phloem. Leaves of M. rufa exhibit a double epidermis, thick cuticle, abundant unicellular hairs, large substomatal chambers covered by trichomes and a dense palisade parenchyma. Leaf characters of M. rufa confirm an anatomical adaptation to xerophytic environments.Las especies con frutos carnosos de Myrtaceae están generalmente asociadas a ambientes húmedos y su anatomía vegetativa es principalmente mesofítica. Myrceugenia rufa es una especie rara y endémica de lugares secos de la costa de Chile central y no hay estudios anatómicos de sus hojas en términos de adaptaciones ambientales. En este artículo describimos la micromorfología y anatomía foliar de la especie usando protocolos estándar para microscopia óptica y electrónica de barrido. La anatomía foliar de M. rufa es similar a otras especies de Myrtaceae, en lo que respecta a presencia de drusas, canales secretores esquizógenos y floema interno. Las hojas de M. rufa tienen una epidermis doble, cutícula gruesa, pelos unicelulares abundantes, cavidades subestomáticas amplias y cubiertas por tricomas, y un denso parénquima en empalizada. Los caracteres foliares de la especie confirman una afinidad morfoanatómica a ambientes xerofíticos

Zur Anatomie und Physiologie der Zuwachszonen- und Jahresringbildung in den Tropen

Distinct zones of growth were usually only found in tropical deciduous trees with a periodically resting cambium. Reversedly a periodically resting cambium proved not to produce always distinct zones. All possible combinations of cambial activity and the formation of zones were shown to occur in the tropics. The zones could be distinguished in cross-sections by a) radial compression of the fibres formed before the new burst of cambial activity, b) a thin circular layer of parenchyma, c) a thin layer of libriform fibres, d) alternating widths of layers of libriform fibres and parenchyma, e) layers alternating in vessel diameter or arrangement. Most species formed either marked zones in east and west Java or less marked or irregular zones in the more even climate of west Java. Only a few species formed no growth zones at all in the more even climate.Young trees often did not form growth zones or only temporary ones, so that the zones were not a direct indication of age. Imported evergreen trees (except leafy trees with individually flushing branches) from cooler climates had no zones or vague ones. Renewed growth in leafy trees was always induced by substances or stimuli conducted from the sprouting leaf buds (and later from leaves) or from flowers (in leafless trees)

De micrografische identificatie van hout

The timber of dicotyledonous trees could not be classified on microscopic features in harmony with taxonomic practice because botanical systems were still faulty and not generally recognized, and because microscopic descriptions of timber were not uniform enough for compilation. To find whether timber features could be conformed with a botanic taxonomy, a scheme was drafted for the description of secondary wood of dicotyledonous trees based on definite, uniform and comparable characteristics.On this basis short descriptions were compiled of the timber of 93 species and a table was composed of species identical in microscopic structure. The 24 most important characteristics of the 42 families represented were described. Families and species were indexed.</p

Comparative wood anatomy of the blueberry tribe (Vaccinieae, Ericaceae s.l)

Wood samples of 111 Vaccinieae specimens (Vaccinioideae, Ericaceae s.l.) representing 98 species and 26 genera are investigated with light microscopy and scanning electron microscopy. The wood structure of Vaccinieae delivers taxonomically important characters that can be used to define some subclades within the tribe. The wood of the large polyphyletic genus Vaccinium strongly resembles non-vaccinioid members of the family, which are characterized by bordered vessel-ray pits and relatively narrow (2- to 4-seriate) and low multiseriate rays (often less than 1000 m) with exclusively or mainly procumbent body ray cells. The East Malesian clade, Meso-American/Caribbean clade, and the Andean clade show a combination of wood anatomical features that is lacking in other representatives of the family. These features include scalariform vessel-ray pits with strongly reduced borders, a high portion of upright body ray cells, wide (4- to 14-seriate) and high multiseriate rays (often more than 3000 m), and prismatic crystals in chambered ray cells (although absent in Symphysia racemosa). The presence of secretory ducts in the primary xylem and in the pith tissue may represent a synapomorphy for the Andean clade. Furthermore, the presence of undivided axial parenchyma cells, usually ranging from 500 to 900 m, seems to be unique in the subfamily.  FWN – Publicaties zonder aanstelling Universiteit Leide

Systematic anatomy of the woods of the tiliaceae

This archival publication may not reflect current scientific knowledge or recommendations

Estudo anatômico do xilema secundário e da casca de algumas espécies dos generos acácia e mimosa, nativas no estado do Rio Grande do Sul

O presente trabalho tem por objetivo contribuir para o conhecimento anatômico de algumas espécies de Legaminosae Mimosoideae do sul do Brasil. Foram estudadas a madeira e casca de 5 espcies de ocorrôncia abundante no Estado do Rio Grande do Sul, e pouco conhecidas anatomicamente: Acacia bonariensis Gili. ex llook. et Arn. ; Acacia caven (Mol.)Mol. Acacia tucumanensis Gris. ; Mimosa bimucronata (D.C.)O.Ktze. e Mimosa scabrella Benth. Para fins de comparação foi anali sada a estrutura da madeira de outras 2 espcies de Mimosa, e 6 do gônero Acacia. As espcíes são descritas individualmente, incluindo caracterfsticas botânicas, estrutura geral, macrosc6pica e microsc6pica da madeira, e estrutura anatômica da casca. São tamb6m fornecidos os nomes comuns, distribuição geogrfica, hbitat, e utilizações das espcios estudadas. Foram elaboradas chaves de identificação baseadas em caracteres anatômicos da madeira e casca. Sãd discutidos a variabilidade intra-especifica dos caracteres anatômicos do xilema, e o valor da anatomia da ma deira e casca para a identificação de espcies dos gôneros Acacia e Mimosa. Os resultados obtidos indícaram uma alta heterogeneidade estrutural do xilema nos gêneros e sibilitando uma fácil separação das ospcíes estudadas. As diferenças na estrutura anatmica do xilema dentro do gnero Acacia, bem como no gncro Mimosa, permitem a sepa ração das espécies estudadas conforme as subdivisões destes gêneros propostas por Bentham. A variabilidade observada na estrutura anatômica da casca suficientemente alta entre as espécies estudadas e fixa dentro de uma determinada espcie, para permitir uma fácil identificação atravs da anatomia da casc